Investigation of the superconducting energy gap in the compound LuNi2B2C by the method of point contact spectroscopy: two-gap approximation Academic Article uri icon

abstract

  • It is shown that the two-gap approximation is applicable for describing the dVdI(V) spectra of LuNi2 B2 C-Ag point contacts in a wide interval of temperatures. The values and the temperature dependences of the large and the small gaps in the ab plane and in the c direction were estimated using the generalized BTK model [A. Plecenik, M. Grajacar, S. Benacka, P. Seidel, and A. Pfuch, Phys. Rev. B 49, 10016 (1994)] and the equations of S. I. Beloborodko, Fiz. Nizk. Temp. 29, 868 (2003) [Low Temp. Phys. 29, 650 (2003)]. In the BCS extrapolation the critical temperature of the small gap is 10 K in the ab plane and 14.5 K in the c direction. The absolute values of the gaps are 0 ab =2.16 meV and 0c =1.94 meV. For the large gaps the critical temperature Tc coincides with the bulk, Tcbulk =16.8 K, and their absolute values are very close, being about 3 meV in both orientations. In the c direction the contributions to the conductivity from the small and the large gaps remain practically identical up to 10-11 K. In the ab plane the contribution from the small gap is much smaller and decreases rapidly as a temperature rises. 2006 American Institute of Physics.

published proceedings

  • LOW TEMPERATURE PHYSICS

author list (cited authors)

  • Bobrov, N. L., Beloborod'ko, S. I., Tyutrina, L. V., Chernobay, V. N., Yanson, I. K., Naugle, D. G., & Rathnayaka, K.

citation count

  • 9

complete list of authors

  • Bobrov, NL||Beloborod’ko, SI||Tyutrina, LV||Chernobay, VN||Yanson, IK||Naugle, DG||Rathnayaka, KDD

publication date

  • April 2006